Power supply systems are pervasive in many electronic applications from computers to automobiles. Generally, voltages within a power supply system are generated by performing a DC-DC, DC-AC, and/or AC-DC conversion by operating a switch loaded with an inductor or transformer. One class of such systems includes switch-mode power supply (SMPS). An SMPS is usually more efficient than other types of power conversion systems because power conversion is performed by controlled charging and discharging of the inductor or transformer and reduces energy lost due to power dissipation caused by resistive voltage drops.
Specific topologies of SMPS include buck converters, boost converters, buck-boost converters and fly-back converters, among others. Depending on the topology selected and the needs of a particular system, the SMPS may be implemented using a half-bridge architecture, a full bridge architecture, or with any other implementation known in the art.
A transformer may be used in some cases, such as in the case of a fly-back converter. For example, a DC-DC converter including a transformer may have a full bridge in the primary side of the transformer and may have diodes in the secondary side of the transformer to perform the rectification process. In some cases, synchronous rectifier techniques may be used, in part, to improve the efficiency of the system. That is, the DC-DC converter may use switches in the secondary side of the transformer instead of diodes to perform the synchronous rectification process. Each switch in the secondary side may turn on during the time the diode would have been forward biased and may turn off during the time when the diode would have been reversed biased.